The Mallard Report

These are unsettled times for North American populations of Anas platyrhynchos. The mallard was among the first bird species named by Linnaeus in 1758, with a name that comes from the Latin Anas, meaning “duck,” and platyrhynchos, meaning “broad-billed.” That settled what to call these beloved birds, but in more recent years, knowing just what is and just what isn’t a wild mallard, and keeping track of their population status across multiple flyways, has become increasingly complex.

It turns out that the subpopulations of the good ol’ greenhead are quite varied. Some migrate thousands of miles. Some are year-round residents. Some are as wild as their ancestors were at the end of the last Ice Age. Others are showing alarmingly high signatures of genetic material from Old World mallard stocks, following decades of game-farm mallard releases into the wild. As complex as mallard populations are, however, this is still North America’s favorite duck. And everyone in the waterfowl world has a stake in ensuring the well-being of one of the most recognizable birds on the planet.

There is no simple answer to the question of how mallards are doing. To work through the fog, we’ll take a closer look at the three separate breeding stocks that are independently monitored and managed in North America: the western population, the midcontinent population, and the eastern population. Like all human-derived lines on a map, the borders of these regions are porous, and mixing among these populations is common. But with these distinct mallard stocks in mind, and with the results of truly groundbreaking research coming into focus, we have a clearer picture than ever about the status of the ever-popular greenhead.

And a clearer picture of the challenges ahead.

Mallard Manor

Given that mallards are not a homogeneous group, it might help to think of them as a bunch of college kids in a dormitory with three floors. We’ll call it Mallard Manor. On the first floor are members of the midcontinent stock of mallards, which mainly include birds that are produced in the Prairie Pothole Region of the United States and Canada as well as in the Western Boreal Forest and other northern breeding areas. These are stout, hardy birds from fine, upstanding backgrounds. These are the greenheads that your mother wants your sister to bring home. These birds flood the Mississippi and Central Flyways each hunting season, bringing joy and fabulous duck fajitas to much of the country.

But on the eastern end of the floor are a couple of rooms full of the Great Lakes kids. These birds breed in Minnesota, Michigan, and Wisconsin. They’re considered part of the midcontinent stock, but to be honest, they sort of keep to themselves. They’re fine ducks, in general, but more than a few of them are starting to hang out with some real troublemakers. Those third-floor mallards—we’ll get to them in a minute.

On the second floor of Mallard Manor are the western stock birds. They’re largely from Alaska, British Columbia, Washington, Oregon, California, and other western states. They have their issues, but on the whole, those are the hip, cool kids. They’re natty dressers on the second floor. And they are a tight-knit group.

And that leaves the third-floor crowd: the eastern mallard hangout. What a train wreck. Fast-food bags everywhere. Beds are never made. They’re nice enough, but there’s something off with those ducks. A lot them would rather hang out downtown than spend a weekend in the countryside. What kind of mallard does that? There’s a growing consensus: it’s a good idea to stay away from the third floor.

There you have it: North America’s Mallard Manor. One species, three floors, a mix of friend groups, and a lot of questions about what makes a mallard a mallard. No wonder managing this crowd has become so challenging.

Western Stock

Let’s start with those western birds first, up on the second floor. Walled off by the Rocky Mountains, they sort of do their own thing. It’s not that they don’t have their problems, but challenges in the Pacific Flyway are somewhat more straightforward than those in other regions. This stock includes birds that breed in Alaska and British Columbia, which are included in the traditional area surveyed by the US Fish and Wildlife Service and Canadian Wildlife Service during the annual Waterfowl Breeding Population and Habitat Survey (WBPHS). It also includes mallards that breed in Washington, Oregon, and California, where state agency surveys provide additional population data.

On one hand, the most recent survey numbers provide a sigh of relief for western waterfowlers. In 2024, mallard numbers were up 46 percent in Alaska and the Western Boreal Forest—a jump that was a whopping 36 percent above the long-term average. Those birds can make their way to hunters as far away as Arizona, and any increase is welcome news.

But for mallard populations that breed in the western contiguous states, the news is less cheery. In California, for example, breeding mallards were down 12 percent in 2024, dragging the population to a level 45 percent below the long-term average. Such a local decline is particularly disheartening. According to Dr. Daniel Smith, waterfowl scientist for DU’s Western Region, “What we raise in spring and summer is what we have in fall and winter. Approximately 80 percent of mallards harvested in California are hatched and raised in California. It’s a similar situation in Oregon and Washington but less pronounced, as a larger influence of Canada birds exists in these states.”

And across the West, as in other breeding areas, what matters most to mallards is what’s happening when it’s time to lay eggs. “In this region, breeding habitat really dictates what we’re going to see in terms of birds during the hunting season,” Smith says. “Habitat losses occurring in the arid West are acute. We have especially seen a decline in grassland, pasture, and cereal grain crops, which mallards can nest in.”

Which only underscores the critical nature of wetlands and upland conservation for these ducks.

Midcontinent Stock

The first floor of Mallard Manor presents some particularly sticky wickets. The midcontinent population of mallards includes all the mallards that breed in the traditional survey area covered by the WBPHS, minus Alaska. It also includes a subpopulation—mallards that breed in Minnesota, Michigan, and Wisconsin. Those are often referred to as Great Lakes mallards. Altogether, this population includes more than 95 percent of the mallards harvested annually in the Mississippi and Central Flyways.

Dealing with those first two issues is hardly a new challenge, and DU and other wetland conservation partners have proven approaches for mitigating their impacts. But the issue of game-farm mallard hybridization with wild mallards is causing increasing concern among waterfowl managers. That’s only been heightened with the results of a groundbreaking study of Great Lakes greenheads. Between 2021 and 2023, Michigan State University doctoral student Ben Luukkonen—now Dr. Ben Luukkonen, waterfowl biologist for the Coeur d’Alene Tribe of Idaho—led a project that outfitted 592 captured female mallards with solar-powered GPS transmitters and collected blood samples from each bird for genetic analysis. Data from birds captured during spring and summer in Michigan, Wisconsin, Illinois, Indiana, and Ohio poured in. Luukkonen ended up with more than 4 million GPS locations, an incredible trove of information about the fine-scale movements and behavior of these mallards.

His findings have done nothing to diminish the concern over game-farm mallard genetics in wild populations. “Among the most shocking findings was the proportion of hybrids in the samples,” Luukkonen says. Only 44 percent of hens were considered wild mallards. The others were game-farm mallard and wild mallard hybrids.

Equally noteworthy were differences in behavior between the wild and hybrid birds, teased out by the wealth of GPS location data. In the study, researchers looked at urban areas as well as high-quality natural habitats. The marked mallards with hybrid genetic signatures showed a decided preference for a different kind of habitat than wild birds did—they flocked to urban settings, where they turned out to be particularly poor parents. Mallards with high percentages of game-farm genes were less likely to incubate than wild birds were. They would lay eggs on sidewalks and in landscaping. Productivity of these birds was poor compared to that of fully wild birds.

Hybrid birds were also more likely to hang around the same area than wild birds were. “The more domestic ancestry in the birds,” Luukkonen explained, “the shorter the daily average distance traveled and the less likely the birds were to engage in migration.”

Paired with the GPS study was a detailed analysis of long-term band return data from mallards in the region. “This is a huge data set,” Luukkonen says, “and we only have it because hunters report information from banded birds that they harvest. It allows us to ask the hard questions. Has survival in mallards declined? Has productivity declined? Have they both declined, and is there a relationship between the two that we need to know about?” The data suggests that both survival and productivity of female mallards have indeed fallen from past levels. And the core factor “most correlated with these declines,” Luukkonen points out, “is the loss of the number of acres enrolled in the federal Conservation Reserve Program.” While hybridization is an issue, it is worsened by a loss of quality habitat.

“There’s a lot we still need to learn about the impacts of genetic changes and the relationship to mechanisms that might lead to decline,” says Dr. John Coluccy, director of conservation planning in DU’s Great Lakes/Atlantic Region. Is declining productivity purely a result of the environments these birds are more likely to visit, where there is greater disturbance and predators? Is it mostly rooted in genetic changes? Or is it a combination of these factors? “It’s an ever-evolving process when we’re talking about science and research,” Coluccy explains.

If those concerns are growing in the Great Lakes, they are supercharged to the east.

Eastern Stock

Take a deep breath, and let’s head to Mallard Manor’s third floor. In the Atlantic Flyway, less than 15 percent of mallards taken by hunters are hatched in the WBPHS traditional survey area. The majority of eastern stock mallards breed in what is known as the eastern survey area of Ontario, Quebec, and Canada’s Atlantic provinces as well as the northeastern United States. With an estimated population of 1.169 million birds in 2024, eastern mallards were down 4 percent from the 2023 estimate and were 9 percent below the long-term average. But those estimates come within the context of a more than 40 percent drop in mallard numbers in the eastern United States over the last two decades. And there’s another confounding rub: mallard populations in eastern Canada have remained fairly stable during the same period.

Overall, mallard numbers in the Atlantic Flyway were never large. The region was historically the realm of the American black duck until the mid-20th century, when hundreds of thousands of farm-raised mallards—largely from domestic Old World lineages—were released annually in eastern states. Those released birds were the source of game-farm mallard genes in the Atlantic Flyway, and today it’s difficult to find a truly wild mallard breeding in the east. In a recent landmark study, researchers found that 71 percent of Atlantic Flyway mallards contained farm-raised mallard ancestry. And those genes are moving west. According to recent genetic research, nearly one in four Mississippi Flyway mallards contained Old World haplotypes (groups of genes or DNA variants), as did 12 percent of mallards from the Central Flyway.

Luukkonen’s GPS study of those nearly 600 marked mallard hens wrapped up just as another critical mallard study shifted into high gear. Beginning in 2022, researchers in the Atlantic Flyway placed GPS trackers on nearly 1,000 female mallards, a massive collaborative project between Ducks Unlimited, State University of New York–Brockport, New York State Department of Environmental Conservation, Pennsylvania Game Commission, University of Saskatchewan, and nearly two dozen other partners. Similar to the Great Lakes mallard study, researchers plan to use their findings to help tease apart the factors that are driving the population differences in mallards breeding on different sides of the US–Canada border.

And those studies are also being bolstered by the “duckDNA project,” a collaboration between DU and the University of Texas at El Paso in which waterfowl hunters collect genetic material from mallards and other ducks harvested during hunting season across the United States. The third floor of Mallard Manor might be a raucous crowd, but there are plenty of smart people keeping tabs on them.

Moving Forward

What’s clear is that mallard populations in North America are in a moment of great flux, and their management is at an inflection point. “There is so much work going into the study of what drives these mallard populations,” Coluccy says. “We are learning that these are entirely different systems, responding to a multitude of factors.” While concern is rising over the present status and future prospects of North America’s favorite duck, it’s being matched with a strengthening commitment to conserve the places these ducks need to thrive.

In 2017, three DU scientists in the pages of this very magazine predicted that “15 or 20 years from now it will be a new generation of DU biologists who will provide an update in Ducks Unlimited magazine on the status of our most abundant, adaptable, and popular duck.” Yet only eight years later mallard population dynamics have changed so much, and so dramatically, that a new status report is needed. (And as for that “new generation” of biologists, there are plenty in the field. But all three of the writers of that prescient article—Drs. Mark Petrie, John Coluccy, and Mike Brasher—are still hard at it for DU.)

Perhaps that’s the most important takeaway of all: the broad-billed, orange-legged, broad-chested, green-headed (only the males, of course) quacker is in need of greater study, greater scrutiny, and a greater commitment to conservation. Because no matter how things have changed for the mallard, one thing remains steadfast: This is a bird worthy of all the consternation, concern, and wonder it inspires.